boards/nucleo-f303re: Fixed/extended SPI conf

boards/nucleo-f303re/include/periph_conf.h

@@ -177,7 +177,17 @@ static const spi_conf_t spi_config[] = {
         .apbbus   = APB2
     },
     {
-        .dev      = SPI1,
+        .dev      = SPI2,
+        .mosi_pin = GPIO_PIN(PORT_B, 15),
+        .miso_pin = GPIO_PIN(PORT_B, 14),
+        .sclk_pin = GPIO_PIN(PORT_B, 13),
+        .cs_pin   = GPIO_PIN(PORT_B, 12),
+        .af       = GPIO_AF5,
+        .rccmask  = RCC_APB1ENR_SPI2EN,
+        .apbbus   = APB1
+    },
+    {
+        .dev      = SPI3,
         .mosi_pin = GPIO_PIN(PORT_C, 12),
         .miso_pin = GPIO_PIN(PORT_C, 11),
         .sclk_pin = GPIO_PIN(PORT_C, 10),